O. Selinus, B. J. Alloway, J. A. Centeno, R. B. Finkelman, R. Fuge, U. Lindh and P. Smedley, “Essentials of Medical Geology, Impacts of the Natural Environment on Public Health,” Elsevier Academic Press, Waltham, 2005.
 S. Rapant, M. Letkovicova, V. Cveckova, K. Fajcíkova, J. Galbavy and M. Letkovic, “Environmental and Health Indicators of the Slovak Republic,” Monograph, State Geological Institute of DionyzStur, Bratislava, 2010.
 S. Rapant, K. Vrana and D. Bodis, “Geochemical Atlas of Slovakia-Part I. Groundwater,” Monography, Ministry of the Environment of the Slovak Republic, Geological Survey of Slovak Republic, Bratislava, 1996.
 S. Rapant, K. Vrana and J. Curlik, “Environmental risk from the Contamination of Geological Compartments of the Environment of the Slovak Republic,” Geological Survey of Slovak Republic, Bratislava, 2004.
 C.-Y. Yang, H.-F. Chiu, B.-H. Cheng, T.-Y. Hsu, M.-F. Cheng and T.-N. Wu, “Calcium and Magnesium in Drinking Water and the Risk of Death from Breast Cancer,” Journal of Toxicology and Environmental Health, Vol. 60, No. 4, 2000, pp. 231-241. doi:10.1080/00984100050027798
 S. C. Larsson, L. Bergkvist, J. Rutegard, E. Giovannucci and A. Wolk, “Calcium and Dairy Food Ontakes Are Inversely Associated with Colorectal Cancer Risk in the Cohort of Swedish Men 1’2’3,” The American Journal of Clinical Nutrition, Vol. 83, No. 3, 2006, pp. 667-673.
 E. Kesse-Guyot, S. Bertrains, B. Dupernay, N. Amault, A. Barhen, P. Galan and S. Hercberg, “Dairy Products, Calcium and the Risk of Breast Cancer: Results of the French SU.VI.MAX Prospective Study,” Annals of Nutrition and Metabolism, Vol. 51, No. 2, 2007, pp. 139-145.
 L. M. Butler , A. S. Wong , W. P. Koh, R. Wang, J. M. Yuan and M. C. Yu, “Calcium Intake Increases Risk of Prostate Cancer among Singapone Chinese,” Cancer Research, Vol. 70, No. 12, 2010, pp. 4941-4948. doi:10.1158/0008-5472.CAN-09-4544
 W.-H. Steeb, “The Nonlinear Workbook: Chaios, Fractals, Neutral Networks, Genetic Algorithms, Gene Expression Programming, Support Vector Machine, Wevelets, Hidden Markov Models, Fuzzy Logic with C++, Java and SymbolicC++ Programs,” 4th Edition, World Scientific Publishing, Singapore City, 2008.
 “ACT on Protection and Land Use of Agricultural Soil and on Ammendment of Act No. 245/2003 on Integrated Prevention and Control of Environment Pollution and on Ammendment and Supplement of Some Other Acts,” 2004.
 G. R. Brenniman and P. S. Levy, “Epidemiological Study of Barium in Illinois Drinking Water Supplies,” In: E. J. Calabrese, R. W. Tuthill and L. Condie, Eds., Inorganics in Water and Cardiovascular Disease, Princeston Scientific Publishing Co., Princeston, 1985, pp. 231-240.
 R. G. Wones, B. L. Stadler and L. A. Frohman, “Lack of Effect of Drinking Water Barium on Cardiovascular Risk Factors,” Environmental Health Perspectives, Vol. 85, 1990, pp. 355-359. doi:10.2307/3430694
 T. Agusa, T. Kunito, J. Fujihara, R. Kubota, T. B. Minh, P. T.-K. Trang, H. Iwata, A. Subramanian, P. H. Viet and S. Tanabe, “Contamination by Arsenic and Other Trace Elements in Tube-Well Water and Its Risk Assessment to Humans in Hanoi, Vietnam,” Environmental Pollution, Vol. 139, No. 1, 2006, pp. 95-106. doi:10.1016/j.envpol.2005.04.033
 S. Rapant, V. Cveckova, Z. Dietzová, M. Letkovicova and M. Khun, “Medical Geochemistry Research in SGR Mts,” Environmental Geochemistry and Health, Vol. 31, No. 1, 2009, pp. 11-25. doi:10.1007/s10653-008-9152-2
 J. M. Chan, E. Giovannucci, S.-O. Andersson, J. Yuen, H.-O. Adami and A. Wolk, “Dairy Products, Calcium, Phosphorous, Vitamin D and Risk of Prostate Cancer (Sweden),” Cancer Causes and Control, Vol. 9, No. 6, 1998, pp. 559-566. doi:10.1023/A:1008823601897
 C. Rodriguez, M. L. McCullough, A. M. Modul, E. J. Jacobs, D. Fakhrabadi-Shokoohi, E. L. Giovannucci, M. J. Thun and E. E. Calle, “Calcium, Dairy Products, and Risk of Prostate Cancer in a Prospective Cohort of United States Men,” Cancer Epidemiological Biomarkers Preview, Vol. 12, No. 7, 2003, pp. 597-603.
 J. Ahn, D. Albanes, U. Peters, A. Schatzkin, U. Lim, M. Freedman, N. Chatterjeen, G. L. Andriole, M. F. Leitzmann, R. B. Hayes, Prostate, Lung, Colorecta and Ovarian Trial Project Team, “Dairy Products, Calcium Intake, and Risk of Prostate Cancer in the Prostate, Lung, Colorectal, and Avarian Cancer Screening Trial,” Cancer Epidemiological Biomarkers Preview, Vol. 16, No. 12, 2007, pp. 2623-2630. doi:10.1158/1055-9965.EPI-07-0601
 P. N. Mitrou, D. Albanes, S. J. Weinstein, P. Pietinen, P. R. Taylor, J. Virtarno and M. F. Leitzmann, “A Prospective Study of Dietary Calcium, Dairy Products and Prostate Cancer Risk (Finland),” International Journal of Cancer, Vol. 20, No. 11, 2007, pp. 2466-2473. doi:10.1002/ijc.22553
 G. W. Rowland, G. G. Schwartz, E. M. John and S. A. Ingles, “Calcium Intake and Prostate Cancer among African Americans: Effect Modification by Vitamin D Receptor Calcium Absorption Genotype,” Journal of Bone Miner Research, Vol. 27, 2012, pp. 187-194.